Which word has a different stress pattern from that of the others?

She is interested in learning English.

Rewrite each of the following sentences in another way so that it means almost the same as the sentence printed before it. 

Mary sings better than her elder sister does.

Mary is _______________________________.

Choose the word / phrase / sentence (A, B, C or D) that best fits the space or best answers the question given in each sentence. (3.5 pts).

Which word has the underlined part pronounced differently from that of the others?

They find it easy to understand native speakers.

They have no _______________________________.

My father used to smoke cigarettes.

My father doesn't _______________________________.